Alternatively, bale buildings can have a structural frame of other materials, usually steel or timber-frame, with bales simply serving as insulation and plaster substrate, (“infill” or “non-load-bearing” technique), which is most often required in wet climates. In wet climates, the imperative for applying a vapor-permeable finish such as lime or lime and earthen renders commonly used on load-bearing bale walls. Additionally, the inclusion of a skeletal framework of wood or metal allows the erection of a roof prior to raising the bales, which can protect the bale wall during construction, when it is the most vulnerable to water damage in all but the most dependably arid climates. A combination of framing and load-bearing techniques may also be employed, referred to as “hybrid” straw bale construction.
Straw bales have also been used in very energy efficient high performance buildings such as the S-House in Austria which meets the Passivhaus energy standard. In South Africa, a five-star lodge made from 10,000 straw bales has housed luminaries such as Nelson Mandela and Tony Blair. In the Swiss Alps, in the little village of Nax Mont-Noble, construction works will start in 2011 for the first hotel in Europe built entirely with straw bales.
Below are some photographs of a very large straw bale in-fill home that we helped to build near Sydney. It was a complex build with high expectations for the finished walls NOT to look like a straw bale home. It is an in-fill or post and beam construction, complex with many quirks and fine detail. It was not low cost! The majority of straw bale homes these days are built using the in-fill method with a variety of frames supporting the roofs and second stories. We prefer the Huff ‘n’ puff Hybrid method to in-fill methods these days.